The purpose of this project is to study the regulation of the enzymes involved in methane oxidation in the facultative methane-oxidizing bacterium, Methylobacterium organophilum, strain R6. The approach to this problem will involve both physiological and genetic studies. The methane mono-oxygenase, methane-oxidation and the internal membrane content will be measured in cells grown in continuous culture on several carbon and energy sources. The induction and repression of these functions will also be determined. Mutants which are unable to grow on methane will be isolated and characterized. A genetic transfer system will be developed and the mutants will be mapped against themselves and against marker mutants. The lesions will be localized in the chromosome or in the methane plasmid. This study will clarify the mechanism of regulation of methane oxidation and define which genes involved in methane oxidation are carried on the methane plasmid and which, if any, are carried on the chromosome.